1,309 research outputs found

    Spatial modeling with repopulation potential for three flora species of Huaytapallana Regional Conservation Area, Peru

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    In the high mountain ecosystems of the Huaytapallana Regional Conservation Area (ACR-H) there are three species of flora (Krapfia macropetala, Gentianella scarlatinostriata and Senecio canescens) of social, economic, cultural and medicinal importance, however their population status and undefined local distribution make these species area more vulnerable to extinction. Therefore, the objective of this work is to determine the population distribution for repopulation purpose in the ACR-H from the potential distribution in Peru using Maxent algorithm and a local model developed with the Saaty pairwise hierarchy matrix, adding a soil sample for a better application of the final model. The results show that the Species Distribution Models (SDMs) have a high confidence because the Area Under the Curve (AUC) surpass 0.90. Otherwise, the local model is consistent by showing a Consistency Ratio (CR) of less than 0.10. As a final result, all species obtained optimal spaces for repopulation near the Huaytapallana Cordillera, where Krapfia macropetala obtained the largest extension (715.334 ha) and Gentianella scarlatinostriata is the smallest (650.096 ha). Further there were no differences in the parameters evaluated in the three soil samples, which facilitates the application of the models for the repopulation of these three species

    Diseño estructural de una edificación de diez pisos con semisótano en la Ciudad de Cajabamba, Departamento Cajamarca

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    El presente proyecto de investigación se realizó en la provincia de Cajabamba, departamento de Cajamarca, lugar donde se determinó el diseño estructural de una edificación de 10 pisos con semisótano. Para el desarrollo del proyecto de investigación se empleó un diseño no experimental, transversal, un muestreo no probabilístico por juicio de expertos, la recolección de datos se llevó a cabo con la técnica de la observación y del análisis documental, utilizando como instrumentos la ficha de resumen y la guía de observación, la estadística descriptiva para el análisis de datos. El gran problema que existe es la gran demanda de edificaciones en la provincia de Cajabamba que no cuentan con el equipamiento y la seguridad necesaria para brindar servicios de calidad y comunidad, Como resultados se obtuvo una edificación con una óptima distribución y un análisis mediante el software ETABS donde se pudo determinar que la estructura cuenta con una excelente rigidez, con derivas máximas en el sentido “X” de 0.00665 y en “Y” de 0.00685 cumpliendo con lo establecido en las normas E.030 Y E0.60. y luego de haber comprobado se dio inicio a la elaboración de planos necesarios para dicho proyecto de investigación

    Enhanced Actin Pedestal Formation by Enterohemorrhagic Escherichia coli O157:H7 Adapted to the Mammalian Host

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    Upon intestinal colonization, enterohemorrhagic Escherichia coli (EHEC) induces epithelial cells to generate actin “pedestals” beneath bound bacteria, lesions that promote colonization. To induce pedestals, EHEC utilizes a type III secretion system to translocate into the mammalian cell bacterial effectors such as translocated intimin receptor (Tir), which localizes in the mammalian cell membrane and functions as a receptor for the bacterial outer membrane protein intimin. Whereas EHEC triggers efficient pedestal formation during mammalian infection, EHEC cultured in vitro induces pedestals on cell monolayers with relatively low efficiency. To determine whether growth within the mammalian host enhances EHEC pedestal formation, we compared in vitro-cultivated bacteria with EHEC directly isolated from infected piglets. Mammalian adaptation by EHEC was associated with a dramatic increase in the efficiency of cell attachment and pedestal formation. The amounts of intimin and Tir were significantly higher in host-adapted than in in vitro-cultivated bacteria, but increasing intimin or Tir expression, or artificially increasing the level of bacterial attachment to mammalian cells, did not enhance pedestal formation by in vitro-cultivated EHEC. Instead, a functional assay suggested that host-adapted EHEC translocate Tir much more efficiently than does in vitro-cultivated bacteria. These data suggest that adaptation of EHEC to the mammalian intestine enhances bacterial cell attachment, expression of intimin and Tir, and translocation of effectors that promote actin signaling

    Microglial GPR56 is the molecular target of maternal immune activation-induced parvalbumin-positive interneuron deficits

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    Parvalbumin-positive (PV+) interneurons play a critical role in maintaining circuit rhythm in the brain, and their reduction is implicated in autism spectrum disorders. Animal studies demonstrate that maternal immune activation (MIA) leads to reduced PV+ interneurons in the somatosensory cortex and autism-like behaviors. However, the underlying molecular mechanisms remain largely unknown. Here, we show that MIA down-regulates microglial Gpr56 expression in fetal brains in an interleukin-17a-dependent manner and that conditional deletion of microglial Gpr56 [Gpr56 conditional knockout (cKO)] mimics MIA-induced PV+ interneuron defects and autism-like behaviors in offspring. We further demonstrate that elevated microglial tumor necrosis factor-α expression is the underlying mechanism by which MIA and Gpr56 cKO impair interneuron generation. Genetically restoring Gpr56 expression in microglia ameliorates PV+ interneuron deficits and autism-like behaviors in MIA offspring. Together, our study demonstrates that microglial GPR56 plays an important role in PV+ interneuron development and serves as a salient target of MIA-induced neurodevelopmental disorders

    The RIVUR Voiding Cystourethrogram Pilot Study: Experience with Radiologic Reading Concordance

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    Published cohorts of children with vesicoureteral reflux placed on antibiotic prophylaxis differ in baseline characteristics and methodology. These data have been combined in meta-analyses to derive treatment recommendations. We analyzed these cohorts in an attempt to understand the disparate outcomes reported

    Adenovirus vector expressing Stx1/Stx2-neutralizing agent protects piglets infected with Escherichia coli O157: H7 against fatal systemic intoxication

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    Hemolytic-uremic syndrome (HUS), caused by Shiga toxin (Stx)-producing Escherichia coli (STEC), remains untreatable. Production of human monoclonal antibodies against Stx, which are highly effective in preventing Stx sequelae in animal models, is languishing due to cost and logistics. We reported previously that the production and evaluation of a camelid heavy-chain-only V(H) domain (VHH)-based neutralizing agent (VNA) targeting Stx1 and Stx2 (VNA-Stx) protected mice from Stx1 and Stx2 intoxication. Here we report that a single intramuscular (i.m.) injection of a nonreplicating adenovirus (Ad) vector carrying a secretory transgene of VNA-Stx (Ad/VNA-Stx) protected mice challenged with Stx2 and protected gnotobiotic piglets infected with STEC from fatal systemic intoxication. One i.m. dose of Ad/VNA-Stx prevented fatal central nervous system (CNS) symptoms in 9 of 10 animals when it was given to piglets 24 h after bacterial challenge and in 5 of 9 animals when it was given 48 h after bacterial challenge, just prior to the onset of CNS symptoms. All 6 placebo animals died or were euthanized with severe CNS symptoms. Ad/VNA-Stx treatment had no impact on diarrhea. In conclusion, Ad/VNA-Stx treatment is effective in protecting piglets from fatal Stx2-mediated CNS complications following STEC challenge. With a low production cost and further development, this could presumably be an effective treatment for patients with HUS and/or individuals at high risk of developing HUS due to exposure to STEC

    A Novel Strategy for Development of Recombinant Antitoxin Therapeutics Tested in a Mouse Botulism Model

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    Antitoxins are needed that can be produced economically with improved safety and shelf life compared to conventional antisera-based therapeutics. Here we report a practical strategy for development of simple antitoxin therapeutics with substantial advantages over currently available treatments. The therapeutic strategy employs a single recombinant ‘targeting agent’ that binds a toxin at two unique sites and a ‘clearing Ab’ that binds two epitopes present on each targeting agent. Co-administration of the targeting agent and the clearing Ab results in decoration of the toxin with up to four Abs to promote accelerated clearance. The therapeutic strategy was applied to two Botulinum neurotoxin (BoNT) serotypes and protected mice from lethality in two different intoxication models with an efficacy equivalent to conventional antitoxin serum. Targeting agents were a single recombinant protein consisting of a heterodimer of two camelid anti-BoNT heavy-chain-only Ab VH (VHH) binding domains and two E-tag epitopes. The clearing mAb was an anti-E-tag mAb. By comparing the in vivo efficacy of treatments that employed neutralizing vs. non-neutralizing agents or the presence vs. absence of clearing Ab permitted unprecedented insight into the roles of toxin neutralization and clearance in antitoxin efficacy. Surprisingly, when a post-intoxication treatment model was used, a toxin-neutralizing heterodimer agent fully protected mice from intoxication even in the absence of clearing Ab. Thus a single, easy-to-produce recombinant protein was as efficacious as polyclonal antiserum in a clinically-relevant mouse model of botulism. This strategy should have widespread application in antitoxin development and other therapies in which neutralization and/or accelerated clearance of a serum biomolecule can offer therapeutic benefit

    A calculus of expandable stores: Continuation-and-environment-passing style translations

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    LICS 2020 will be held onlineInternational audienceThe call-by-need evaluation strategy for the λ-calculus is an evaluation strategy that lazily evaluates arguments only if needed, and if so, shares computations across all places where it is needed. To implement this evaluation strategy, abstract machines require some form of global environment. While abstract machines usually lead to a better understanding of the flow of control during the execution, facilitating in particular the definition of continuation-passing style translations , the case of machines with global environments turns out to be much more subtle. The main purpose of this paper is to understand how to type a continuation-and-environment-passing style translation , that is to say how to soundly translate in continuation-passing style a calculus with global environment. To this end, we introduce Fϒ , a generic calculus to define the target of such translations. In particular, Fϒ features a data type for typed stores and a mechanism of explicit coercions witnessing store extensions along environment-passing style translations. On the logical side, this broadly amounts to a Kripke forcing-like translation mixed with a negative translation (for the continuation-passing part). Since Fϒ allows for the definition of such translations for different source calculi (call-by-need, call-by-name, call-by-value) with different type systems (simple types, system F), we claim that it precisely captures the computational content of continuation-and-environment-passing style translations

    Enlarging conference learning : at the crossroads of fat studies and conference pedagogies

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    This article stages an encounter between the field of fat studies and conference pedagogy scholarship. After laying the foundations for a reading of academic conferences as learning spaces, the authors present two examples—International Fat Studies Conferences held in Aotearoa, New Zealand, in 2012 and 2016—to unpack these ideas. The framing of fat studies conferences as pedagogical spaces sparks questions that travel in multiple directions. It calls us to consider possible modifications to the design of fat studies conferences, as well as how discussions about fat pedagogy may have a wider application to academic gatherings
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